This invention relates to a fuel injection pump for an internal combustion engine, such as a diesel engine.
Diesel engines are supplied with fuel by means of fuel injection pumps. These injection pumps force fuel into the engine combustion chambers periodically with respect to rotation of the engine crankshafts.
The variation of the rate of fuel injection with the rotational angle of the crankshaft during each fuel injection stroke affects fuel combustion characteristics. In particular, the fuel combustion characteristics sensitively depend on the amount of fuel injected during the initial stage of each fuel injection stroke relative to the amount of fuel injected during the rest of the stroke. From the standpoint of reducing fuel combustion shocks, engine vibration and noise, and of reducing harmful engine emissions, it is desirable to decrease the proportion of fuel injected during the initial stage of each fuel injection stroke.